Apparatus for providing shutter release and for indicating end of a controlled time exposure

ABSTRACT

Apparatus for actuating a camera shutter to uncover an exposure aperture, for actuating switch means, and for indicating the end of a controlled time exposure, including a shutter actuating member movable from a first position to a second position for actuating the shutter to uncover the exposure aperture. The shutter actuating member is retained in the second position during a controlled time exposure, and is released for return movement to the position in response to the actuation of the shutter to cover the exposure at the end of the controlled time exposure. The returning of the shutter actuating member to the first position indicates the end of the controlled time exposure.

United States Patent [191 Harvey [541 APPARATUS FOR PROVIDING SHUTTERRELEASE AND FOR INDICATING END OF A CONTROLLED TIME EXPOSURE [75]Inventor: Donald M. Harvey, Webster, [73] Assignee: Eastman KodakCompany,

Rochester, NY.

[22] Filed: Aug. 19, 1971 [21] Appl. No.: 173,196

[52 Us. c|. ..9s/10 CT, 95/11 R, 95/53 EB, 95/60 [51] Int Cl. ..G03b7/08, G03b 9/16, G03b 17/18 [58] Field of Search ..95/ 10 C, 10 CT, 11R, 53 R, I 95/53 EA, 53 EB, 53.3, 59, 60

[56] References Cited UNITED STATES PATENTS 3,421,427 1/1969 Starp..95/53 EA X Feb. 13, 1973 4/1966 Kagan "95/53 EB 3,479,935 11/1969Harvey ..95/l0 CT 3,418,910 12/1968 Reutschler et al ..95/53.3

Primary Examiner-Joseph F. Peters, Jr. AttorneyW. H. J. Kline et a1.

[ 5 7 ABSTRACT Apparatus for actuating a camera shutter to uncover anexposure aperture, for actuating switch means, and

for indicating the end of a controlled time exposure,

including a shutter actuating member movable from a first position to asecond position for actuating the shutter to uncover the exposureaperture. The shutter actuating member is retained in the secondposition during a controlled time exposure, and is released for returnmovement to the position in response to the ac tuation of the shutter tocover the exposure at the end of the controlled time exposure. Thereturning of the shutter actuating member to the first positionindicates the end of the controlled time exposure.

5 Claims, 4 Drawing Figures P/u'm furunalm 3,715,959

v sum 10F 2 SWITCH/N6 DE W65 DONALD MI'IARVEY INVENTOR.

I BY

AT ORIVEYS PATENTEDFEB 13 I975 3.715.959

SHEET 2 UF 2 fP/VEYS exposure v mechanismsof various forms, includingboth mechani- APPARATUS FOR PROVIDING SHUTTER RELEASE AND FOR INDICATINGEND OF A CONTROLLED TIME EXPOSURE BACKGROUND OF THE INVENTION directedto the total'automation of film exposure control apparatus.Consequently, cameras are available which incorporate various forms oftiming devices,

such as electronic light measuring circuits, cooperating withshutterarrangements so that the shutter system is adjustedjautomatically. Thecontrolled timecxposure frequently lasts for several seconds, dependingupon the scene illumination, and during these long exposure intervals itis extremely difficult not to transmit some motion to thecamera.Transmitting motion to the camera is particularly a problem where theoperator does not know the exact moment when the shutter mechanismcloses to terminate the exposure. Several approaches have been used toindicate to the operator that the controlled time exposure hasterminated. For example,.in the case of electronically-controlled timeexposure, there is often provided a light which is ener-' gi'zed duringexposure, and deenergized to indicate the end of the exposure interval.

The present invention is directed to a simple mechanism for providing anindication of the end of an interval, that is useful with timing cal andelectrical types.

' SUMMARY OF THE INVENTION It is therefore an object of the invention toprovide an improved method and apparatus for indicating the end of theexposure cycle for controlled time exposures. I

In one illustrative embodiment of the invention, a shutter actuatingmechanism for use in a camera includes a shutter actuating memberdisposable a first to a second position including means for maintainingthe depression of the shutter actuating member during the controlledtime exposure, and means to effect release of the shutter actuatingmember at the end of the controlled time exposure so that it returns tothe first position. The returning shutter release member is readilydetected by the eye or touch of a camera operator and provides anindication of the end of the controlled time exposure.

In a specific embodiment of the invention the shutter actuatingmember,when moved to the second position, actuates a switch to provideelectronic time control, and releases shutter means for initiating theexposure. The shutter means maintains the shutter actuating member inthe second-position during the controlled time exposure. Movement of theshutter means to terminate the exposure releases the shutter actuatinmember for movement to the first position.

2 BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of theinvention will become apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of a shutter mechanism, incorporating ashutter actuating member, shown-in the cocked position of the shuttermechanism and the normal position of the shutter actuating member;

FIG. 2 is an elevational view of the shutter mechanism of FIG. 1, in theuncooked position, showing the shutter actuating member depressed andengaging a closing shutter blade during the controlled time exposure;

FIG. 3 is an elevational view of the shutter mechanism of FIGS. 1 and 2,at the end of the controlled time exposure, when the closing shutterblade releases the shutter actuating member for movement to the normalposition; and

FIG. 4 is a schematic diagram of a suitable electronic circuit for usewith the apparatus of FIG. 1.

DETAILED DESCRIPTION OF TIIE DRAWINGS Because cameras are well known,the present description will be directed to elements forming part of, orcooperating more directly with the disclosed embodiment of theinvention. Camera partsnot specifically shown or described may takeforms well known to those skilled in the art.

Referring now to the drawings, and in. particular to FIG. 1, oneembodiment of the invention is shown in the blade 16 is retained in acocked, open position cooperation with a shutter mechanism mounted on acamera structure 10. The camera structure 10 defines an exposureaperture 12, aligned with a camera exposure axis, indicated by the lineA, through which scene illumination passes during exposure. The shuttermechanism includes an opening shutter blade 14 and a closing shutterblade 16, each defining a pair of elongated slots 20 for receiving apair of pins 18 secured on the camera structure 10. Each of the shutterblades 14 and 16 is movably mounted by means of the associated pins andslots for movement in the direction indicated by the arrow B, to uncoverand cover the exposure aperture 12. In FIG. 1, the blade 14 is shown inits aperture blockingor closed position, and the blade 16 is shown inits open or apertureunblocking position. In FIG. 2 the blade 14 hasmoved laterally from the aperture blocking to the aperture unblockingposition, and the aperture is exposed to incident scene light. FIG. 2also shows a timing switch 82 which is actuated by the blade 14 upon theopening movement of the blade 14. FIG. 3 shows the blade 16 afterlateral movement of the blade 14, to the aperture closing position forterminating the exposure of the aperture 12 to incident scene light.

The blade 14 is retained in a cocked, closed position as shown in FIG.1, against the bias of a spring 22, by a shutter actuating mechanism 25,which is to be more fully described later. Prior to initiation of anexposure,

against the bias of spring 24 by engagement of a front end of the blade16 with a back edge of the blade 16.

After initiation of an exposure, the blade 16 is held by a device suchas an electromagnet 26, which may be energized by a suitable electronictiming circuit, to be described later. When energized, the electromagnet26 attracts a keeper 27 on the blade 16, and retains the blade 16 in theposition shown in FIG. 2.

As further shown in FIG. 1 the shutter actuating mechanism includes anelongated shutter actuating member 28, which may have a portion 30accessible from the camera exterior for manual actuation, and which isreceived in a slot 31 formed in a camera housing 32. Themember 28 isreceived within the slot 31 for axial movement, against the bias of aspring 29, from a first, or normal position as shown in FIG. 1, to asecond, or release position as shown in FIG. 2. The member 28 ismaintained in the position of FIG. 1, by means of an angular extension34 engaging a downward extending wall structure 33 of the camera housing32. The bias of the spring 29 maintains the extension 34 in engagementwith the wall structure 33. The extension 34 is provided with a notch36, which in the cocked position of the blade 14 shown in FIG. 1,engages a pin 38 on the blade 14, to retain the blade 14 in the cockedposition against the bias of the spring 22. The extension 34 is alsopositioned in relation to a switch S1, so that initial axial movement ofthe member 28 actuates the switch S1 to a closed position. As furthershown in FIG. 1, the member 28 is provided with a downwardly projectinglatch member 42. The latch member 42 may be a resilient irregular leafspring member 43, and when the member 28 moves axially against the biasof the spring 29 as shown in FIG. 2, the member 43 bends and snaps undera bent over portion 44 on the top of the blade 16. The shutter actuatingmechanism 25 is thereby latched in its release position, against thebias of the spring 29.

The circuit shown in FIG. 4 is an example of timing means such as may beemployed with the shutter mechanism of FIG. 1. In the disclosedembodiment the timing means comprises a conventional light-integrating,electronic circuit and includes a voltage source 40, a transistorswitching device 50, an electromagnet coil 52, and a voltage integratingnetwork including a photocell 53 connected in series with a capacitor 54across the source 40. The capacitor 54 is shunted to ground by theintegrating switch S2. The switch S2 is normally closed so that thecapacitor 54 is normally completely discharged. Thus, when the switch S2is opened, by the blade 14, as shown in FIG. 2, the voltage at ajunction 46 between the photocell 53 and the capacitor 54 changes fromits initial value in a period of device 50 to switch from its conductivestate to its nonconductive state. The switching of the switching device50 to its nonconductive state terminates the flow of current in the coil52, and the electromagnet 26 becomes deenergized. When the electromagnet26 becomes deenergized, the closing shutter blade 16 is released formovement, under the bias of the spring 24, to cover the exposureaperture 12. The switching device 50 as shown in FIG. 4, may be any ofthe various types of switching devices such as a Schmitt triggercircuit, which is well known in the art.

Inoperation of the shutter mechanism, the shutter actuating mechanism 25is depressed, and the member 28 moves axially from the position of FIG.I to the position shown in FIG. 2. As the member 28 moves axially, thenotch 36 disengages from the pin 38 and the blade 14 moves laterallyunder the bias of spring 22 to expose the aperture 12 to incident sceneillumination, also shown in FIG. 2. Prior to release of the blade 14,axial movement of the member 28 brings the extension 34 into contactwith the switch S and closes the switch S1 for furnishing power to thecircuit of FIG. 4. The circuit energizes the electromagnet 26 and theblade 16 is retained as the electromagnet 26 attracts the keeper 27. Asfurther shown in FIG. 2, the lateral movement of the blade 14 opens thetiming switch S2, initiating the controlled time cycle. Continued axialmovement of the member 28 brings the member 43 of the latch member 42into engagement with the bent over portion 44 of the blade 16, and theshutter actuating mechanism 25 is latched in its release position duringthe period that the blade 16 is in the cocked position. At thetermination of the controlled time exposure, as determined by thecircuit of FIG. 4, the electromagnet 26 becomes deenergized and theblade 16 is released for movement, under the influence of its biasspring 24, to a position covering the exposure aperture 12, as shown inFIG. 3. As further seen by reference to FIG. 3, the movement of blade 16to a position covering the exposure aperture 12, results in release ofthe latch member 42 from the bent over portion 44. Under the timedepending on the well known time constant R-C of the integratingnetwork. The time constant depends upon the capacitance of the capacitor54, and the resistance of the photocell 53, which may in oneillustrative embodiment of this invention be a cadmium sulfidephotocell, which has the property that its impedance varies inverselywith the amount of light incident on the photocell. The junction 46 isconnected to the input terminal of a switching device 50, which isadapted to conduct current through the coil 52 when the bias potentialat the input'is below a predetermined value, and-to be nonconductingwhen its input exceeds that value. The: switching device 50 is normallyconducting when the switch S1 is closed, and when the switch S2 isopened, the voltage level at junction 46 begins to increase to apredetermined value to cause the switching influence of the spring 29,the member 28 returns to the normal position as the blade 16 closes. Thereturn of the member 28 to the normal position indicates to the operatorthat the shutter mechanism has closed, and the controlled time exposurehas been terminated.

The invention has been described in detail with particular reference toa preferred embodiment thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

I claim:

1. In combination with a camera having shutter means actuatable betweenopen and closed conditions for uncovering and covering respectively anexposure aperture, means for moving said shutter means between saidopen'and closed conditions, and means for retaining said shutter meansin said open condition, improved shutter release apparatus comprising:

a member having a portion accessible from the exterior of the camera formanual actuation, said member being movable from a first to a secondposition upon actuation thereof, said member including first meansv forreleasably retaining the shutter means in said closed condition whensaid member occupies said first position, and for releasing said shuttermeansto move to said open condition during actuation of said membertoward said second position, said member including second means forreleasably engaging said shutter means when said member occupies saidsecond position, so that said member remains in said second positionwhen said shutter means is in said open condition; and

means for moving said member to said first position upon movement ofsaid shutter means to said closed condition.

2. Apparatus as claimed in .claim 1 wherein said member includes anelongated portion which is movable axially between said first and saidsecond positions, said first means being disposed angularly from saidportion and said second means comprising a resilient extension of saidportion.

3. Apparatus as claimed in claim 1 wherein said camera includes anelectronic timing circuit for providing an exposure interval related tothe intensity of the scene light, said member being disposed to actuatesaid electronic circuit when said member is moved toward said secondposition.

4. In a camera having shutter control apparatus for establishing theduration of an exposure interval through an exposure aperture, thecombination comprising:

a first shutter blade, movable between a first and second position inrelation to the exposure aperture to block and unblock the exposureaperture respectively;

means urging saidfirst shutter blade to its second position; I

a second shutter blade, movable between first and second positions inrelation to the exposure aperture to unblock and block the exposureaperture respectively;

means urging said second shutter blade to its second position;

an actuatable timing circuit, including photosensitive means disposed toreceive scene light for providing an output signal at the end of theexposure interval, the length of the exposure interval being related tothe intensity of scene light incident on said photosensitive means; I

switch means for activating said timing circuit;

transducer means retaining said second shutter blade in its firstposition, said transducer means respon sive to said signal for releasingsaid second shutter blade to permit movement of said second shutterblade to its second position; and

a shutter actuating member, movable between a first and a secondposition, said member in said first position being located to retainsaid first shutter blade in said first position, said shutter actuatingmember being disposed to release said first shutter blade and actuatesaid switch means upon movement toward said second position, saidshutter actuating member when in said second position being constructedand located to engage said second shutter blade wherein said shutteractuating member is releasably retained in said second position duringthe exposure interval and released to move to said first position uponmovement of said second shutterbladeto its second ositi on. 5. Apparatusas claimed in claim 4 w ereln said shutter actuating member includes adownward extending resilient member and said second shutter bladeincludes a bent-over portion, said resilient member disposed to engagesaid bent-over portion when said shutter actuating member is in saidsecond position, said member being releasable upon movement of saidsecond shutter blade to said closed condition, thereby permitting saidshutter actuating member to move to said first position.

1. In combination with a camera having shutter means actuatable betweenopen and closed conditions for uncovering and covering respectively anexposure aperture, means for moving said shutter means between said openand closed conditions, and means for retaining said shutter means insaid open condition, improved shutter release apparatus comprising: amember having a portion accessible from the exterior of the camera formanual actuation, said member being movable from a first to a secondposition upon actuation thereof, said member including first means forreleasably retaining the shutter means in said closed condition whensaid member occupies said first position, and for releasing said shuttermeans to move to said open condition during actuation of said membertoward said second position, said member including second means forreleasably engaging said shutter means when said member occupies saidsecond position, so that said member remains in said second positionwhen said shutter means is in said open condition; and means for movingsaid member to said first position upon movement of said shutter meansto said closed condition.
 1. In combination with a camera having shuttermeans actuatable between open and closed conditions for uncovering andcovering respectively an exposure aperture, means for moving saidshutter means between said open and closed conditions, and means forretaining said shutter means in said open condition, improved shutterrelease apparatus comprising: a member having a portion accessible fromthe exterior of the camera for manual actuation, said member beingmovable from a first to a second position upon actuation thereof, saidmember including first means for releasably retaining the shutter meansin said closed condition when said member occupies said first position,and for releasing said shutter means to move to said open conditionduring actuation of said member toward said second position, said memberincluding second means for releasably engaging said shutter means whensaid member occupies said second position, so that said member remainsin said second position when said shutter means is in said opencondition; and means for moving said member to said first position uponmovement of said shutter means to said closed condition.
 2. Apparatus asclaimed in claim 1 wherein said member includes an elongated portionwhich is movable axially between said first and said second positions,said first means being disposed angularly from said portion and saidsecond means comprising a resilient extension of said portion. 3.Apparatus as claimed in claim 1 wherein said camera includes anelectronic timing circuit for providing an exposure interval related tothe intensity of the scene light, said member being disposed to actuatesaid electronic circuit when said member is moved toward said secondposition.
 4. In a camera having shutter control apparatus forestablishing the duration of an exposure interval through an exposureaperture, the combination comprising: a first shutter blade, movablebetween a first and second position in relation to the exposure apertureto block and unblock the exposure aperture respectively; means urgingsaid first shutter blade to its second position; a second shutter blade,movable between first and second positions in relation to the exposureaperture to unblock and block the exposure aperture respectively; meansurging said second shutter blade to its second position; an actuatabletiming circuit, including photosensitive means disposed to receive scEnelight for providing an output signal at the end of the exposureinterval, the length of the exposure interval being related to theintensity of scene light incident on said photosensitive means; switchmeans for activating said timing circuit; transducer means retainingsaid second shutter blade in its first position, said transducer meansresponsive to said signal for releasing said second shutter blade topermit movement of said second shutter blade to its second position; anda shutter actuating member, movable between a first and a secondposition, said member in said first position being located to retainsaid first shutter blade in said first position, said shutter actuatingmember being disposed to release said first shutter blade and actuatesaid switch means upon movement toward said second position, saidshutter actuating member when in said second position being constructedand located to engage said second shutter blade wherein said shutteractuating member is releasably retained in said second position duringthe exposure interval and released to move to said first position uponmovement of said second shutter blade to its second position.